Applications of ruthenium hydride borohydride complexes containing phosphinite and diamine ligands to asymmetric catalytic reactions

A series of novel trans-ruthenium hydride borohydricle complexes with chiral phosphinite and diamine ligands were synthesized. They can be used in the asymmetric transfer hydrogenation of aryl ketones, including base-sensitive ones, to give chiral alcohols in moderate to good enantioselectivities (up to 94% eel. They are also efficient catalysts for the Michael addition of malonates to enones with enantioselectivities of up to 90%. This kind of catalyst allows a one-pot tandem Michael addition/H-2 hydrogenation protocol to build structures with multiple chiral centers.